[Effects of nicotine on action potentials of guinea pig and rabbit papillary muscles].
The electrophysiological action of nicotine was studied by microelectrode technique on isolated guinea pig and rabbit papillary muscles. Nicotine had no significant effect on RP, APA and Vmax; but its biphasic effect on APD35, APD90 and ERP were observed in different concentrations, ie: high concentration (604 mumols/L) prolonged APD35, APD90 and ERP by 27.3, 26.0 and 26.1% respectively, whereas low concentration (0.6 mumol/L) shortened them by 49.6, 40.0 and 27.6%, respectively. It is suggested that high concentration of nicotine may enhance the calcium influx, but low concentration decrease it.
Wang
Q S
QS
Department of Physiology, Zhang-jiakou Medical College, China.
Yin
J X
JX
Liu
T F
TF
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009538:Nicotine / Q000494:pharmacology*; D010210:Papillary Muscles / Q000187:drug effects*; D011817:Rabbits; D012032:Refractory Period, Electrophysiological / Q000187:drug effects
D009538:Nicotine